I have a rotator cuff injury that goes back years. I have been doing band exercises to strengthen it the last few months. I am willing to become a semipro swimmer if that would make an improvement in it, but I don't want to waste the time if I won't see results. Has anyone heard of someone or they themselves did this to help such an injury?

I would say definately yes, even though i'm no expert, slowly flailing and rotating my arms in varied semi/full-circles with really light weight has seemed to be somewhat effective in helping me, but im definately not 100% yet.

in addition, 2 people have told me that swimming was helpful in their recovery.

With swimming, you are doing that, but it makes it appear that you are doing it for a legitimate reason, and you have a little resistance without being overwhelmingly heavy, in all directions, unlike just with gravity downwards aka free weights. Whenever trying to exercise gently i find people staring and pointing

But, I am so out of shape that i dont want to be swimming at this point